In Microsoft Visio, a point is a single value that embodies a pair of x - and y -coordinates. If the shape is in a group, its parent is the group. If the shape is not in a group, its parent is the page.
In this expression, PNT converts a pair of coordinates in the current shape into a point. PAR then converts the point into a pair of coordinates in relation to the lower-left corner of the page or group that contains the current shape.